Is there any way to drill a hole in an object?The model I want to make is technical rather than artistic.I would like to be able to cut out parts of the 3d object using a hard line sculpting tool like a drill or wood caving knife.Is there any way I can do that?

Ok, thanks for those methods.I am trying subtract from parent and wanted to know how I determine which part is the parent?I have a sphere and a cylinder (small diameter longer length) which I have placed into the centre so all views show the cylinder is going through the sphere.I pressed k to do the meshIf the sphere is the parent and I want to do a subtract from parent which one do I select and when do I use the mesh, subtract from parent?

Only thing I can add to the steps above it to make sure that drag and parent happens OK in the groups panel. You should see a "-" by the Sphere, and moving the sphere should move both objects now. Then with the cylinder selected use "Cut from Parent"

OK, there was no - next to the sphere in the groups list.Moving the cylinder over and to the right of the sphere made the minus appear.I did try object group after using Ctrl and select each object but that did not seem to do the same. I did expect it to.

The hole crafted into the sphere is as round as yours.Can I smooth the edges somehow?